1. Field of the Invention
The present invention relates to a method and a device for providing communication data that provide the communication data including a communication address such as an IP (Internet Protocol) address that identifies a device on a mobile object at the time of communication with respect to the device on a mobile object that is installed on a mobile object like a vehicle that travels on, e.g., a track and constitutes at least a part of a network system that performs communication in accordance with a predetermined communication protocol such as Internet Protocol via an LAN (Local Area Network).
The present invention also relates to a data gathering system for a mobile object and a device on a mobile object for this system that collects mobile object information concerning a mobile object stored in a device on a mobile object, the device on a mobile object installed on a mobile object such as a vehicle traveling on a track communicating with a ground device that is installed on the ground by using wireless communication data including a communication address such as an IP address set to the device on a mobile object for identifying the device on a mobile object in accordance with a predetermined communication protocol such as Internet Protocol via a wireless LAN.
The present invention also relates to a network system for organizing vehicles and an on-vehicle device for the system, the on-vehicle device installed in each vehicle in a vehicle unit including a plurality of vehicles traveling on, e.g., a track performing communication by using communication data including a communication address such as an IP address set to the on-vehicle device for mutual identification in accordance with a predetermined communication protocol such as Internet Protocol via an LAN.
2. Description of the Related Art
There has heretofore been a data gathering system for a mobile object or a network system for organizing vehicles as a network system that is at least partially constituted of a device on a mobile object installed on a mobile object such as a vehicle traveling on a track and performs communication in accordance with a predetermined communication protocol such as Internet Protocol via an LAN (Local Area Network). As the conventional data gathering system for a mobile object, in the field of, e.g., railroad, there is known a system that records and stores vehicle information such as operation histories of many mounted devices mounted in each vehicle as a mobile object organizing a train in a recording medium in an on-vehicle device as the device on a mobile object installed in each vehicle, brings back this recording medium itself or another recording medium such as an IC card having information stored in the recording medium therein, and reads this information into a ground device installed on the ground from the recording medium to gather the vehicle information, thereby utilizing the gathered information to effect maintenance operations for the mounted devices at appropriate timings. Further, there is also known that vehicle information recorded and stored in a recording medium in an on-vehicle device is transmitted from the on-vehicle device to a ground device at predetermined fixed clock times or at fixed time intervals or by a manual operation via a serial transmission line to gather the vehicle information in the ground device (see, e.g., Patent Document 1).
In the former data gathering system for a mobile object, however, an operator must go the round of the vehicles gathered in, e.g., a large rail yard, manually bring out a recording medium from the ground device, and read vehicle information into the ground device from the recording medium, and collection of the vehicle information is a very troublesome operation.
Further, the latter data gathering system for a mobile object does not take a lot of trouble but has a problem that a public line network must be utilized to transmit vehicle information from the on-vehicle device on each vehicle of a train to the ground device via the serial transmission line while traveling and a communication charge is produced to increase a running cost.
Thus, as a system that does not take the trouble of gathering vehicle information and has no high running cost, there is considered a system that an on-vehicle device on each vehicle of trains gathered in a rail yard is connected with a ground device installed in the rail yard through a wireless LAN and vehicle information stored in a recording medium in the on-vehicle device is automatically gathered in the ground device installed in the rail yard via the wireless LAN.
Furthermore, as a conventional network system for organizing vehicles, there is known a system that monitors and controls an on-vehicle device including a terminal device such as each of various mounted devices mounted in each vehicle in a vehicle unit in the field of, e.g., railroad (see, e.g., Patent Document 2). Incidentally, as monitoring and control, there are monitoring a state of a specific on-vehicle device in each vehicle, e.g., a specific one of service devices such as an air-conditioning equipment in each vehicle and control over an operation of such a device, monitoring a state of a specific door or a brake in each vehicle and control over an operation of this device, and others. Moreover, a door, an air-conditioning device, a brake, an ATO (Automatic Train Operation), automatic announcement, SIV (Static Inverter), a motor and others correspond to the mounted devices.
Patent Document 1: Japanese Patent Application Laid-open No. 251702-1996
Patent Document 2: Japanese Patent Application Laid-open No. 2006-20117
In all the systems described above, when specifying a device on a mobile object or an on-vehicle device installed in each of many vehicles (which will be abbreviated to an “on-vehicle device” hereinafter) to perform communication in accordance with a predetermined communication protocol via an LAN, communication data such as a communication address in a format determined based on the communication protocol must be set to each on-vehicle device to specify the on-vehicle device. When the communication address is, e.g., an IP (Internet Protocol) address (which will be referred to as an “IP address” hereinafter), as provision for setting, there are a dynamic address providing scheme for preparing a server that manages IP addresses and automatically providing a temporal IP address in response to a request from an on-vehicle device and a static address providing scheme for providing a static IP address in advance.
When providing a dynamic IP address, a DHCP server having a dynamic host configuration protocol (which will be referred to as “DHCP” hereinafter) implemented therein is often used. In the DHCP server, a range of IP addresses that may be assigned to on-vehicle devices is set, an IP address is selected from the IP addresses that may be assigned to the on-vehicle devices, and the selected IP address is temporarily provided to the on-vehicle device that has accessed. When the on-vehicle device terminates communication using the IP address provided thereto, the DHCP server automatically collects the address and assigns it to another on-vehicle device.
When this DHCP is used, the trouble of setting communication data in a network can be omitted to readily achieve connection using an IP address. However, when the IP address automatic providing method based on this DHCP is utilized, a correspondence relationship between an on-vehicle device and an IP address changes with time, and hence there is a problem that managing the correspondence relationship between the on-vehicle device and the IP address is difficult. Additionally, when communication is interrupted and an IP address is again provided, the IP address of an on-vehicle device may be different from a previous one, there is a problem that access to the on-vehicle device has a disadvantage.
In case of providing a static IP address, since the static IP address is provided to each on-vehicle device in advance, a fluctuation in address that is observed in the dynamic address providing scheme can be avoided, and there is no problem involved by the fluctuation in address. However, as an operation of providing the static IP address to each on-vehicle device in advance, the static IP address that should be provided is manually input by a key operation. Therefore, an operator must go to a vehicle having an on-vehicle device as a provision target installed therein, which is troublesome, and a wrong static IP address may be possibly provided by an operation mistake of an operator. Further, this providing operation is performed in not only initial installation of each on-vehicle device but also malfunction, regular maintenance for each vehicle and remounting each on-vehicle device, and hence a frequency of the manual providing operation is very high.
When an on-vehicle device is erroneously specified due to a mistake in the manual providing operation and an address that is not a connection target is provided, communication cannot be achieved in some cases. Furthermore, for example, if an IP address is redundantly provided, on-vehicle devices may be confused.
Generally, in case of the wireless LAN, to mutually identify a ground device and some of on-vehicle devices and achieve wireless communication between them via the wireless LAN in accordance with a predetermined IP protocol, respective pieces of wireless communication data such as a user ID, a user password and others are set besides the IP address. In particular, when the on-vehicle devices adopt a cable LAN configuration, a routing table is also set as communication data. However, when the communication data including this routing table is provided by a manual operation, the same problem as that in case of the IP address occurs. Such a problem also occurs in a system that an on-vehicle device installed in each vehicle and a terminal device installed in each vehicle communicate with each other by utilizing different addresses preset to the on-vehicle device and each terminal device to monitor and control the terminal device such as each of various mounted devices mounted in each vehicle in a vehicle unit.
Therefore, in view of the above-described points, it is an object of the present invention to provide a method and a device for providing communication data that provide communication data for identifying a communicating device on a mobile object with respect to the device on a mobile object that is installed on the mobile object and constitutes at least a part of a network system that performs communication in accordance with a predetermined communication protocol through an LAN without a problem of manually providing the communication data.
In view of the above-described points, it is another object of the present invention to provide a data gathering system for a mobile object and a device on a mobile object for this system that gather mobile object information stored in each device on a mobile object in a ground device without a problem of manually providing wireless communication data.
In view of the above-described points, it is still another object of the present invention to provide a network system for organizing vehicles and an on-vehicle device for this system that have a configuration where a terminal device installed in each vehicle in a vehicle unit communicates with the on-vehicle device installed in the vehicle through an LAN in accordance with a predetermined communication protocol by using communication data set to the on-vehicle device for mutual identification without a problem of manually providing the communication data.